One of the key men behind Bill Ackman's bet on Valeant is leaving to launch a healthcare startup

One of Bill Ackman's key researchers on Valeant is leaving
Pershing Square and plans to launch a startup focused
on reducing healthcare costs.

Jordan Rubin, a member of Ackman's 10-person investment team, is
leaving Pershing Square Capital Management in the coming weeks
after seven years at the firm.

As an investment analyst, Rubin, 32, contributed to positions
including Valeant Pharmaceuticals International, Zoetis, Allergan
and Family Dollar.

"I think extremely highly of Jordan," Ackman told
Business Insider. "He's a very talented, hard
working, smart person, and I think he's going to be
enormously successful with his new venture."

Rubin and Bill Doyle, who also recently left Pershing
Square, led the research that resulted in Pershing Square's
"partnership with Valeant in its efforts to merge with Allergan,"
according to a
2014 letter filed with the SEC.

The Pershing Square L.P. fund fell -16.2% last year after posting
36.9% gains the year before, according to a
Pershing Square document. Pershing Square Holdings, a
publicly traded vehicle that is a proxy for Ackman's hedge fund,
is
down -17.8% through August 16.

Andy
Kiersz / Business Insider

Rubin joined Pershing Square in 2009 after a stint
at Goldman Sachs, where he worked as an analyst in the
special situations group.

In a statement to Business
Insider, Rubin said he was "grateful for the opportunity to
have contributed to many profitable and innovative investments at
Pershing Square" and that he is "excited to begin the next stage"
of his career.

"I hope to follow in the
footsteps of other successful Pershing Square alumni who have
chosen an entrepreneurial path," he said, adding that
he plans to continue to invest in Pershing Square's
fund.

Rubin is partnering with an unnamed healthcare
entrepreneur for the startup, which will target reducing
healthcare costs and is set to launch later this
year.

Other prominent staffers have also departed the firm in
recent months. In May, the firm announced that
Bill Doyle, who was also behind the Valeant bet, was leaving.

But there have also been additions. Jenna Dabbs, a former federal
prosecutor in New York who was hired last year as senior
counsel, joined Ackman's investment staff earlier this summer,
making her the first woman ever on the team.